Potato Cannon Instructions

By Tom Mayo, July 28, 2002

Here are some general instructions on how you can make a potato cannon. This cannon will fire potato slugs at around 150 miles per hour up to hundreds of feet.

I take no responsibility for any injuries or property damage that occur with this toy. A potato cannon is capable of causing serious injury either with an impact of the potato or with an explosion of the cannon itself.

First you must gather materials:

·  1/4" thick 1 1/2" diameter PVC barrel (around 5 feet plus or minus)

·  1/4" thick 4" diameter PVC chamber (around 1 1/2 feet plus or minus)

·  1/4" thick barrel to chamber reducer

·  saddle tee (rides on top of chamber with no penetration)

·  1 1/2" grip (around 1 foot long plus or minus)

·  end cap for grip

·  gas grill sparker

·  heavy gauge wire

·  wire nuts

·  2 1/4 x 20 x 3" bolts and six nuts

·  1/4" thick end cap for 4" chamber

·  1/4" thick screw cleanout for chamber end cap

·  PVC cement

·  spray solvent, hair spray, or ether, etc. for propellant

Now assemble the cannon:

·  cut and cement together all the PVC parts as shown.

·  note: the grip assembly should only require cement between the saddle and the grip tube, not to the chamber or the grip end cap.

·  drill holes for the gas grill sparker, sparker bolts, and sparker wire escapes.

·  wire the sparker to the sparker bolts through the grip and sparker wire escape holes.

·  note: keep the wires away from each other as they could short out before the spark bolts and not cause a spark in the chamber.

·  note: keep the wires away from where the operator's arms and legs will be. if the wires come into contact with skin, they will give off a shock, even through insulation.

·  file the inside of the end of the barrel to cut and reduce the potato slugs when loading.

·  wait sufficient time for the cement to dry.

To fire the cannon:

·  Remove the breach cleanout to allow air to escape from the chamber when you ram the potato in the muzzle.

·  Ram the potato into the muzzle using a blunt ram rod (a broomstic with a spool nailed to the end will work).

·  note: the potato should end up at least a couple inches shy of the chamber.

·  spray propellant into the breach.

·  note well: you don't need very much at all (psht).

·  screw the breach cleanout back on.

·  make sure all friendly personnel are clear of the line of fire.

·  depress the firing sparker button.

·  lather, rinse, repeat.

Potato Cannon 2


I started work on another potato cannon today.  This one has some improvements over the first one.  No wiring will be exposed because the bolts are encapsulated within a box.  This will prevent accidental shocks for righties and lefties.  The bolts serve a dual purpose---they also keep the box in place.  Because the two bolts are inline instead of on opposite sides of the chamber, I needed to solder a copper wire to one of the bolts to bridge the gap.  This is possible because I used brass bolts instead of steel.  Brass should stand up to moisture better too.





More updates as construction and testing progress.